That didn't happen. Over the next 20 minutes or so, the Butcherbird moved the body nearly 20 metres and into the thick scrub. The recently dead Blackbird would weigh around 80 grams or so, and the Butcherbird not much more, so it was quite some feat. As you can see in the lower photo, it didn't drag the corpse, but lifted it and walked forward, which was obviously an awkward way to go about it, but it eventually managed to secrete it in the scrub. Whether this is normal behaviour or not I don't know, but the Butcherbird gets its' name from the practice of some of its' relatives, hanging up their prey on thorns on suitable shrubs.
Meanwhile, a few hundred metres away.....Great Egret
In the lower image you may just be able to see the small fish that it has in its' bill, which reminded me of watching Great Egrets in the United States fishing in the backwater of a river where the water was receding fast after a flood. They and a Belted Kingfisher were feasting on the fish floundering in the shallow water. Incredible how many fish they managed to consume in a short time.